IR on the CHEAP

[Don Hoey]

Well I am well impressed with that Harry.

Not sure how my experiments will go today as light levels are pretty low. A quick check of the Met Office satellite sequence shows we are not likely to get much better either.

I see you mention adjusting temp in Lightroom. Does this mean you did not do a Custom WB ?

Don

[wolfie]

Originally Posted by Don Hoey

Well I am well impressed with that Harry.

Not sure how my experiments will go today as light levels are pretty low. A quick check of the Met Office satellite sequence shows we are not likely to get much better either.

I see you mention adjusting temp in Lightroom. Does this mean you did not do a Custom WB ?

Don

Don. You had mentioned having a slight problem with the custom WB, (just a few seconds job on the Canon) so yesterday evening I decided to use raw and adjust the WB on the PC so as to find what I considered an optimum colour temperature.

So yes, as I convert all my raw files via Lightroom. On this occasion I did not do a custom WB.

The weather here is much the as your neck of the woods, so I'm about to redo the horse photo using various other WB settings, if any of these proove to be better than the one posted I will let you know.

Harry

[andy153]

Great Pano Harry, been onto ACS again - another two weeks for the D100, they say they are snowed under.

[Don Hoey]

Originally Posted by wolfie

Don. You had mentioned having a slight problem with the custom WB, (just a few seconds job on the Canon)
Harry

Harry,
I discovered that not only will the D100 not meter with my m/f lenses, but it also will not allow Custom WB. Put an a/f lens on and no probs.
My problem a/f lens wise is I only have 12-24 ( cannot use due to a hotspot ), 35mm, 85mm and 180mm. This has shown m/f lenses have advantages and disadvantages on the D100. At least with m/f I can get to 24mm.

Conditions for testing are not so good. Quite a high wind so the sun comes and goes. Difficult to get a set of directly comparable images at various WB settings. Here is my first effort though, nothing fancy just a shot over the garden fence.

This one is with Custom WB and processing is just a case of convert from RAW to Tiff, Auto levels, run the Action I refered to in post 33, resize and USM .... finished. So with easy processing I will stick with Custom WB for false colour.
Exposure on this is ISO400, 1/6sec at f8, so at least one stop less light loss than the double transparency filter.

Don

[wolfie]

Well it looks as though you've cracked it Don. Now all we need is some decent weather.

You will now have realised the downside of using an IR filter and why I had my old DSLR converted. 1/6 sec does not give much scope when shooting in windy conditions, but a least you're now ble to shoot IR.

Andy, what is the turn round time for a conversion now? From what you say it would seem many people who have upgraded are having their old cameras converted.

Soon all the oldies such as Don will be shooting IR

Harry

[andy153]

Hi Don, you do seem to have cracked it but I am interested in what you say about the 12-24, I assume Nikkor, because apparently the 12-24 DG Sigma is highly recommended for IR. Here is a link to Nikkor lenses and there use with IR.
http://diglloyd.com/prem/prot/DIP/pu...ses-Nikon.html

Hi Harry, ACS got mine on the 17th April, on Friday they told me another two weeks - so about six weeks at the moment. There is a firm on ebay that advertises conversions for £150, and quotes a week to 10 days turn around. These are the people who told me there was no need to retune the auto focus, just stop down to f8. From my reading, that is why I chose ACS and decided the longer wait was worth it.

[Don Hoey]

Originally Posted by wolfie

.........Soon all the oldies such as Don will be shooting IR

Harry

Harry,
Well its all a matter of cost. I just could not afford the covenience that an IR converted camera would give. £35 for a 52mm Hoya R72 filter, although more than my for free film filter, still reasonably falls into the IR on the cheap bracket. Of course the advantage of being an oldie is that I am used to what is by todays standards, more primitive kit.

The next step is to get to fully understand the response of the 3 channels to infrared and get a FAR better understanding of photoshop to be able to play with the subleties of tints.
Keep posting pics here as I am sure I will learn a lot from them.

Andy,
Your link is does not work ...... sign in job so I expect it is a pay to view so I cannot see what you are pointing me at.

12-24 then to quote Bjørn Rørslett, and he is a guy who has done a lot of IR with mostly 'UNCONVERTED TO IR' Nikons, and a huge array of lenses, so who I am I to argue. " IR performance: This lens is frequently severely flawed by a dominant hot-spot. The tendency for hot spotting develops towards the shorter focal settings and is exacerbated when the lens is stopped down. You have to try with your own camera to see if the combination works satisfactorily, the chances are against it though. " By contrast from what I read in a previous link Diglloyd appears to be using converted cameras.

A significant difference here as converted cameras have the AA filter swapped out. At IR wavelengths some lenses suffer a 'hotspot' as a result of light bouncing back and forth between the AA filter the rear lens element. I cannot remember what I was playing around with, ( not IR but maybe flash experiments ), but I have come across this 'hot spot' effect before, and it does not show in normal use. So it is a lens specific phenomenon at certain wavelengths of light. Complexity of the lens design and coatings may well be the factors influencing this. So stunning visible light performance does not equal the same in the IR wavelengths, and equally a mediocre lens in normal light can redeem itself in IR. For example for normal light photography the ancient Sigma 24mm f2.8 I am using for IR cannot hold a candle to my Nikkor 28mm f2.8 AIs. In IR though the 28mm produces a 'hotspot', so in this case the Sigma wins, as it has no 'hotspot'.

For your interest I have a number of AIs lenses in 52mm filter thread that I can test when the sun finally comes out for long enough to conduct a series of consistent tests. - 24mm f2, 28mm f2.8 (tested-hotspot), 50mm f1.4, 55 f2.8 micro, 105mm f2.5, 105mm f2.8 Micro and 200mm f4,

I could have gone the Cokin route despite needing to tape the whole thing up to prevent visible light leak, to allow use of the 85mm, 180mm and Stevies 18-35 on adaptor rings but these lenses lack decent distance markings or in the case of the zoom an IR focus mark. So there is something to be said for old technology after all.

Don

[wolfie]

Hi Don, I realise cost is a great consideration, but I have a delightful wife who still goes to work (should be retired) and is quite happy to pay for these extras for me.

If you follow this link http://diglloyd.com/diglloyd/ReviewInfo.html then scroll down the page you will see an article marked "Now Free". Click on that and follow the various links.

Harry

[Don Hoey]

Originally Posted by wolfie

Hi Don, I realise cost is a great consideration, but I have a delightful wife who still goes to work (should be retired) and is quite happy to pay for these extras for me.

Harry

I showed that to Stevie and she laughed. Still a spend is OK'd if I find a 20mm f3.5 for a good price.

No pics today as the weather has not been on my side. Spent a bit of time making an eye piece blind. Not impressed with what came with the camera.
I read in one of the links that on longer exposures like I am using, it is highly recommended to prevent stay light through the viewfinder degrading the image. That reinforces my view re the Cokin filter and the need to seal the holder from stray light.

Don

[Don Hoey]

Originally Posted by postcardcv

I tried the Cokin IR filter at my local shop ..........

Peter,
I think you must have Mark fired up now. I suggested he join so he could follow this thread.

A bit frustrated with the weather at the moment, but that has lead to another idea. ........ IR with flash. Some of you could probably have guessed that one might come up.

We were in Dereham today, so I popped into Norfolk Camera Centre for something I had ordered, and they had Cokin IR filters on a really good deal. So I got one. The idea is to tape it inside my bellows hood and fire a flash through it. Not sure if it will work but nothing ventured nothing gained. At least that will keep me going until the weather improves. If it works then the next plot will be to try it with a double layer film filter as that is pliable and easier to wrap around a Stofen diffuser.

Of course now I have that, I can test Stevies lenses for hotspots as I am not limited to the 52mm filter thread of the Hoya R72 when I use the bellows hood.

Don